Relief and raising device arrangement in multinip calender

ABSTRACT

A relief and raising device arrangement in a multinip calender or calender stack, in which upon a stationarily rotatable lower roll are mounted two or more superimposed rolls which are pivotably attached by arms to the calender body and in which each roll has its individual relief device attached to a common raising device. The relief devices are so attached to the raising device that the raising device will through the pneumatically regulated relief device constantly be in connection with the roll and that an adjustable free spacing for movement of the relief devices increases in the downward direction. The raising device is preferably a rod movable in vertical direction and attached to the lower or upper part of the calender body.

United States Patent [72] Inventor Paavo J. Laine Tampere, Finland [21 1Appl. No. 704,909 [22] Filed Feb. 12, 1968 [45] Patented Jan. 12, 1971[73] Assignee 0y Tampella Ab Tampere, Finland a corporation of Finland[54] RELIEF AND RAISING DEVICE ARRANGEMENT $155,029 11/1964 ThomasPrimary Examiner-Daniel Blum Attorney-Albert M. Parker [N MULTIN,CALENDER ABS'IIIACT: A relief and raising device arrangement in a Claimssnrawing Figs multlmp calender or calender stack, in wh1ch upon astatlonanly rotatable lower roll are mounted two or more su- [LS- CI- e-imposed rons which are pivotabiy attached arms to the 100/170 calenderbody and in which each roll has its individual relief [51] Ill!- Cl.B301) device attached to a common raising device The relief devices are5 attached 'to the raising device that the raising 163A, 170 device willthrough the pneumatically regulated relief device constantly be inconnection with the roll and that an adjusta- [56] References C'ted blefree spacing for movement of the relief devices increases UNITED STATESPATENTS in the downward direction. The raising device is preferably a2,850,952 9/1958 l-lombostel 100/ 163 rod movable in vertical directionand attached to the lower or 3,044,440 7/1962 Molsberry et a1 100/1 63UXupper part of the calender body.

1/1 lllIlIlllllV/II/ PATEN'TEDJAHIZIQYI 3.654.118 sutnanr a INVENTOR.

PAA v0 J L A/NE ATTORNEY.

l RELIEF AND RAISING DEVICE ARRANGEMENT MULTINIPCALENDER" BACKGROUND orTHE INVENTION LField ofthelnvention: This invention relates. to aportion of the paper machine "known as calender or calender' stack andmore particularly, to

an improvementin a multinip calender. f

2. Description of the Prior Art U.S. Pat. Nos. 2,850,952 and 2,985,100disclose hydraulically or pneumaticallyoperated relief devices, whichact on' the end of a lever mounted on the body and extending to the sideof the calender .body opposite ofthe roll, andin which arrangement theraising device of' the rolls 'a'cts'on that end of said lever whichextends toward theroll, th'at'is on th'e'opposite end withrespect-to therelief i'device. v This arrangement has the drawback that inlthe eventofpaper accumulations squeezing into the nip between two tolls, the end ofthe lever facing. toward the" relief "device loses connection with thehydraulic or pneumatic, relief device, giving ,rise to shocks strainingthe'de-vice. Y I

THE SUMMARY OF Tm; INVENTION This invention relates to a reliefandraising device arrangement in multinip calender stacks of the type inwhichupon a stationarily rotatable lowerv roll are mounted one upon theFlG. l shows a multinip calender stack provided with the re lief andlifting arrangement according toithe invcntiomin side elevation and inpartial section; 2

F IG, 2 is adetail view of a single relief device insection; t

FIG. 3 is a side view of the apparatuss'imilar to theview of FIG. 1 'andwith some parts cut away toshow internal stru ture; j FIG. 3a is adetail view of the liftin g arrangement of FIG. 3 in transverse section;I I

FIG. 4- is a sectional view of. the lower portion of the apparatus ofFIG. 3 and taken at right angles-to the view of FIG. 3; m

FIG. 5 is a detail view, in section, of the relief device oftheinvention;

FIG. 6 is a view, in elevation, of a detail of the relief device;

F IG. 7 illustrates schematically an adjusting screw of the reliefdevice of FIGS. 1 i

' DESCRlPTlGN or, THE PREFERRED EMBODIMENT In the drawing referencenumeral indicates a calender body, Zisabearingfor the lower roll orlt'ing roll 3, reference transmission in housing 10 surrounds theipin 8at its lower end and lifts orlowers the pin 8 by means of trapezoidalthreads on the pin 8 engaging the internal threads of the fitting 9.

The drive means may obviously be any other mechanically or hydraulicallyoperated suitable device.

I At spacedlocations along the lifting rod 7 there are providedadjustable mounted braces or'lugs l 1, below which the relief devicesare mounted. Since the relief devices are arranged between the braces orlugs 11 and the ends of the lever arms 20 the expansion and contractionof the relief devices, braced by the lugsll, serve to raise and lowerthe ends of the lever arms 20. The lever arms 20'are longer than thelever arms 5 to which they are secured at pivot points 6, so the leverarms 5 convey a fraction of the movement of the relief devices to therolls 4, lifting or lowering the rolls. Each of the braces or lugs 11bears a downwardly extending cylindrical element extending into theadjacent relief device.

; The relief device comprises plates and 15 joined together by a bellows13 of annular form. The lower plate 14 is identical in all reliefdevices, and'its upper surface, which remains inside the bellows,consists of an engaging surface 16, and its lower surface is providedwith a central depression, into-which penetrates a stud 18 having at itslower end a T-branch 19 of circular section. This T-b'ranch ispositioned in a recess 21 at the free end of one 20 of the arms of alever. The relief devices are thus pivotallycoupled at 19 to the freeends of the lever arms 20. The upper plate 15 has in its lower surfaceremaining inside the bellows l3 amengaging portion 22, the height ofpneumatic action of the bellow which moves the ends of lever mm 20,through the coupling 19, but'the bellows 13 is also effective to preventthe sudden jarring of the mechanism when a paper accumulation or papercud passes between two rolls v4 of the calender. Because of the highspeeds at which the rolls of modern calenders rotate, the import of apaper cud" passing between two rolls is veryforceful'andmight easilycause the failure of the raising mechanism if it were not for the shockabsorbing effect of the bellows i 1 In the above described reliefandiaisingdevice arrangement according to the invention the supportforce of the roll relief is not applied to the body but through the rollraising rod to thefoundation, which reduces the strains on the bodySudden shocks, as in the case of the passage of a paper cud between towrolls 4, are thus conveyed throughthe raising rod 7 to the worm geartransmission at 10 to thebed or foundation. The arrangement according tothe invention can how-.

numeralA'indica'tes generally the rolls-mountedupon the lower'roll intheyends of arms S-oflevers. The. levers are at points 6 pivotallymounted on the calender body 1, a driving means for a raising rod 7being provided in the lower portion of said body. Beyond their pivotpoints6,- thelevers have arms 20 which arelongerthan the lever arms 5,thus providing a mechanical advantage to the relief devices tobedescribed in detailhereafterp The actuating mechanism for theraising-rod 7 includes a pin 8, which is 'pivotally secured to the lowerend of the raising rod 7.A worm gear transmission mountedon the bedorfloor upon which the calender rests is shown enclosed in a housing 10.An internally threadedfltting 9 rotatable by the worm gear ever beutilized with the raising rod secured tothe upper portion of the body,in case the consequent additional strains on the body are deemed to bewithout'greater importance.

instead of using levers having pivotpoints 6 intermediate their ends asin the above description, it is-also possible to utilize a relief andraising device according to this invention with a different class oflever. Thus the rolls 4 could be secured to levers which have fixedfulcra" at one end and the raising and relief devices at their otherends, the rolls 4 being between the fulcra and the raising and reliefdevices.

The spacing between the engaging surfaces 16 and 22 of the. reliefdevice can be adjusted as required by raising or lowering the threadedmember l2 in the lug .11. Since there is a mechanical advantage in thesystem the individual adjustment of the threaded cylindrical memberslZis done in multiples ofthe spacing which is desired between adjacentrolls 4. Also, because of the cumulative. effect of the adjustmentsit.will be clear that the uppermost lug or brace 11 will be closer tothe end of the adjacent lever arm 20'than the .next lower lug orpneumatic pressure inside the bellows can of course be individuallycontrolled in each device.

In the arrangement of this invention the relief devices constitute apart of the raising device, because of which the rolls 4 through theanns 20 and 5 are in continuous contact through the relief devices withthe raising rod 7, and in the event of paper accumulations squeezinginto the nip between two rolls this relief method and relief devicearrangement provide more resilient shock absorption.

As has been stated above the invention is not restricted to the reliefand raising device arrangement described above and shown in the drawingsbut can be varied within the scope of the following claims.

lclaim:

1. In a paper machine a multinip calender, comprising a calender body, astack of calender rolls including a bottom roll and a plurality ofsuperimposed rolls, separate and independent bearings rotatably carryingthe ends of each of said superimposed rolls and separate arms pivotablyattached to the calender body and independently carrying said bearingsand independent pneumatic relief devices urging each of said bearingsupwardly, said relief devices comprising expandable bellows elements, acommon raising device coupled to said relief devices, said raisingdevice being attached to the calender body for raising and lowering saidbearings and being constantly in contact through said relief deviceswith said bearings, said relief devices having a free spacing increasingin the downward direction.

2. A multinip calender as claimed in claim 1, wherein each of saidsuperimposed rolls is mounted at the end of one arm of a lever pivotablyattached to said calender body, said raising device is provided at theopposite side of the body from said rolls and the said relief devicesare pivotably in connection with the ends of opposite arms of saidlevers.

3. A multinip calender as claimed in claim 1, wherein sai superimposedrolls are mounted on levers pivotably attached to said calender body andsaid relief devices are pivotably secured to free end of said levers.

4. A multinip calender as claimed in claim I, wherein the free spacingfor movement of said relief devices is adjustable.

1. In a paper machine a multinip calender, comprising a calender body, astack of calender rolls including a bottom roll and a plurality ofsuperimposed rolls, separate and independent bearings rotatably carryingthe ends of each of said superimposed rolls and separate arms pivotablyattached to the calender body and independently carrying said bearingsand independent pneumatic relief devices urging each of said bearingsupwardly, said relief devices comprising expandable bellows elements, acommon raising device coupled to said relief devices, said raisingdevice being attached to the calender body for raising and lowering saidbearings and being constantly in contact through said relief deviceswith said bearings, said relief devices having a free spacing increasingin the downward direction.
 2. A multinip calender as claimed in claim 1,wherein each of said superimposed rolls is mounted at the end of one armof a lever pivotably attached to said calender body, said raising deviceis provided at the opposite side of the body from said rolls and thesaid relief devices are pivotably in connection with the ends ofopposite arms of said levers.
 3. A multinip calender as claimed in claim1, wherein said superimposed rolls are mounted on levers pivotablyattached to said calender body and said relief devices are pivotablysecured to free end of said levers.
 4. A multinip calender as claimed inclaim 1, wherein the free spacing for movement of said relief devices isadjustable.